REPORT OF PROF. R. W JONES. 
[21] 
All the foregoing i used frequently and freely diluted with varying quantities of 
water. None of them injured the worms, either on cotton (Heliothis and Aletia) or 
those on cabbage, rate bagas, &c. 
I made a decoction of China leaves and small twigs. This I sprayed freely on the 
cotton plants, and I think it had a large effect in preventing the moths of Heliothis 
and Aletia from ovipositing ; but it did not destroy the larvie. The alcoholic extract 
of the China berries and leaves, adulterated with twice its quantity of water, was 
sprayed on twelve Aletia larvie, full grown. Most of thera fell to the ground, and four 
died. This experiment was repeated several times, with about the same result ; but 
when the extract was diluted with ten parts of water it failed to bring the worms to 
the ground. I concluded from this fact that the cost of the alcohol would be so great 
as to prevent the use of this preparation. 
I made a decoction of elder (Sambucus canadensis), using the leaves, small twigs, and 
berries; also an infusion of the same. This, projected in spray on Aletia, Heliothis, 
and on the worms infesting cabbage, caus< d them to cease eating, and in several in- 
stances caused them to abandon the plant, whether cotton or cabbage. It is well 
known that in all such cases the cotton worm is much more likely to he devoured by 
predaeeOM insects than it is to reascend the plant. 
Pyn thrum. — As an insecticide this is superior, incomparably superior, to all other 
substances with which I have experimented. I used it in powder diluted with wheat 
tlour, and as an extract variously diluted with water. The success attending my ex- 
periments with this were eminently gratifying and satisfactory. 
It maybe proper to remark that 1 used the p\ ret h rum (Buhaeh) raised by G. N. 
Milco, of Stockton, Cal., some sent me from the headquarters of the U. 8. Entomo- 
logical Commission under the name of "Caucasian Insect Powder," and some w hich 
I purchased of Messrs. Bullock Sc Crenshaw, Philadelphia, Pa., as ''Persian Insect 
Powder." 
When used in the state of dry powder, t hat of Milco seene d to havi a considerable 
advantage, but the others seemed to be quite equal to it. in the power to yield deadly 
extracts. 
Mode of preparing powder: 1 part of pyrethrum to 20 parts of wheat-Hour, thor- 
oughly mixed and shut up in a tight tin DOS for twenty-four hours. This blown by 
bellows proved very efficient in dest roying Aletia and cabbage worms which it touched. 
It did not kill squash hugs, though it drove them for tin- time from the plants. It 
killed the Boll Worms upon which it was projected, but did not disturb those that 
were concealed within the bolls. 
Extracts: A. Made with common (ethyl) alcohol !»."> per cent. B. Made with methyl 
alcohol (wood spirit). 
In all my first preparations I proceeded as follows : 
I introduced into a glass flask about 4 ounces of insect pow der and added about 
half a gallon of alcohol, corked and allowed to stand for twenty-four hours. I then 
perforated the cork and introduced a glass t ubo, one fourth of ;ui inch in diameter 
and ">(*) inches long; then subjected the llask to the well regulated beat of a water bath, 
not allowing the temperature to reach the boiling point of alcohol. I usually applied 
this gentle heat for about five hours, then set aside to cool. At first I decanted the 
extract from the residue, and before using, diluted with water, as shown in the ex- 
periments mentioned farther on. Subsequently. I shook up the solid residue of the 
insect powder with the extract and diluted th<' whole wif.b water, and in applying 
kept the solid matter suspended by agitation. I found the latter plan economical! 
The residue being wet with alcohol, readily spreads throughout the water and evi- 
dently adds something to the value of the extract. 
I have never seen any statement or suggestion in regard to the use of wood spii i: 
as the menstruum. It occurred to me to try it. I found it to be a quicker solvent 
of the essential oil and coloring matter of pyrothrum powder than common 96 per 
cent, alcohol. I find that 1 pint and 2 ounces (by measure) of wood spirit will ex- 
tract all the useful material out of an ounce of pyrothrum. Good wood spirits can 
bo bought for §1.25 per gallon. The extract made with wood spirit will bear dilu- 
tion with a somewhat larger quantity of water than the extract made with ethyl al- 
cohol. 
On this point I stato my results thus.; One pound pyrethrum powder to 20 pints (2\ 
gallons) wood spirits. This can bo safely diluted in the earlier part of the season 
when the worms are small with forty parts of water. Hence one pound pyrethrum 
and 2£ gallons methyl alcohol will when diluted make 100 gallons of liquid for the 
destruction of insects. Allowing 40 gallons to the acre, the cost of this insecticide 
would bo $1.50. With improved atomizers this will be lessened. 
Wood spirit is more volatile than ethyl alcohol. This, I think, gives it considerable 
advantage over ethyl alcohol as the solvent for the essential oil of the pyrethrum, 
when the extract is to bo used for Boll Worms that are working on the contents of 
bolls. By its ready volatilizat ion it distributes the insecticide rapidly jnto the adja- 
cent air, and when not directly thrown into the hole cut by the Boll Worm it is car- 
